Skin cancer tissue rapidly identified during surgery
23 September 2013
The University of Nottingham has developed an accurate technique
to rapidly identify the margins of cancerous tissue during surgery
that combines auto-fluorescence of skin tissue with Raman laser
spectroscopy.
The developer team, led by Dr Ioan Notingher in the University's
School of Physics and Astronomy, is now looking to build an
optimised instrument that can be tested in the clinic. The research
has been published in the Proceedings of the National Academy of
Sciences
Dr Notingher said: “By refining our prototype instrument to
make it more user-friendly and even faster to use. Diagnosis of each
tissue layer could be obtained in just a few minutes — rather than
hours. Such developments have the potential to revolutionise the
surgical treatment of cancers. This technology will provide a fast
and objective way for surgeons to make sure that all the cancer
cells have been removed whilst at the same time preserving as much
healthy tissue as possible.”

Pathology specimen showing skin cancer cells
Typically, skin conserving surgery involves cutting away one thin
layer of tissue at a time and carefully examining it to make sure
that all the cancer has been removed. The key is to make sure all
the cancer is removed while preserving as much healthy tissue as
possible to reduce scarring and disfigurement.
Dr Notingher said: “The real challenge is to know where the
cancer starts and ends when looking at it during an operation so
that the surgeon knows when to stop cutting. Our technique can also
diagnose the presence or absence of skin cancer in thick chunks of
skin tissue, making it unnecessary to cut the tissue up further into
thin slices.”
A step forward for BCC
One particular technique, known as Mohs surgery — microscopically
controlled surgery — is used for the treatment of difficult cases of
a type of skin cancer called basal cell carcinoma (BCC). BCC is the
commonest cancer in humans with more than 60,000 new patients
diagnosed each year in the UK.
Mohs surgery provides the highest cure rates for BCC, but
the procedure takes a lot of time because each new tissue layer has
to be frozen and examined during the operation. Typically, this
takes around 1-2 hours per layer so an operation can take as long as
five to seven hours in total. So, from a patient’s perspective,
there is a need to reduce the Mohs surgery time by developing faster
and objective ways of seeing whether the cancer has been completely
removed during a shorter operation under a single local anaesthetic.
Dr Notingher said, “Our technique does not rely on time consuming
and laborious steps of tissue fixation, staining, labelling or
sectioning. The beauty is that it can be automated and very
objective. To make this new technique suitable for use in the middle
of an operation such as Mohs surgery for BCC, we have combined
tissue auto-fluorescence, which is quick and good at picking out all
the cancer cells (but not at excluding normal tissue) as a first
step, followed by Raman scattering, [which is] rather slow but good
at separating normal from cancer tissue. By combining these two
methods into one technique, high accuracy diagnosis of BCC can be
obtained in only a few minutes.”
Professor Hywel Williams, one of the dermatologists working in
the team and Director of the Centre for Evidence Based Dermatology
(CEBD) at The University of Nottingham, said, “I am now convinced
that this technique is reliable and potentially fast enough to
replace conventional methods that determine tumour clearance for
basal cell carcinoma removed during Mohs micrographic surgery — an
advance that will increase the accessibility of Mohs to many more
people across the world.”
This NIHR-funded research was carried out under its Invention for
Innovation (i4i) Programme in collaboration with Nottingham
University Hospital National Health Service (NHS) Trust, Royal
Holloway University, and the CEBD.
Reference
Kong et al. Diagnosis of tumors during tissue-conserving
surgery with integrated autofluorescence and Raman scattering
microscopy. PNAS, vol. 110 no. 38, 15189-15194.